Answer:
no mode , 6 , 6.24
Step-by-step explanation:
Answer:
(a) -3.708
(b) 1.706
(c) 0.490
Step-by-step explanation:
The z-score of normal distribution is given as:

(a)
Given:
Score is, 
Mean value is, 
Standard deviation is, 
z-score is, 
(b)
Given:
Score is, 
Mean value is, 
Standard deviation is, 
z-score is, 
(c)
Given:
Score is, 
Mean value is, 
Standard deviation is, 
z-score is, 
30%
percent means parts out of 100 so 30%=30/100=3/10
42 is 3/10 of x
'of' can be translated to multiply
42=3/10 times x
multiply both sides by 10/3 to get rid of fraction
420/3=x
140=x
the number is 140